<?php

$a;
$a = 10;

$name = 'xuebingsi';
$age = 18;
$sex="男";
$order_id = 456456456;
$orderId = 436534543;
$姓名="学并思";
// $x $X
var_dump($姓名);
///变量是动态类型 松散 弱类型语言
$num = 1000;
$num = 100;
$num = '100';

// int num = 1100;
// num ="dgflodsjgldf";
// 
$a = 100;
$b = $a;//传值赋值
$b = 80;


$a = 100;

$b = &$a;//传址赋值

$b = 80;

var_dump($a);

$a = "b";

$$a = 90; //可变变量，由一个变量的值 决定另外 一个变量的名

var_dump($c);

$a =100;
$b =200;

$c = $a;
$a = $b;
$b = $c;


